1. Field
The present invention relates to a MLCC module, and more particularly, to a MLCC(multi layer ceramic capacitor) module used as a direct current (DC) link capacitor that is included in an inverter of a hybrid vehicle.
2. Background
A hybrid vehicle is driven by an engine and a power of a battery. A force distribution apparatus of the hybrid vehicle includes a fuel battery, a motor, an inverter, a motor control unit (MCU), and a direct current (DC)-to-DC (DC/DC) converter.
The fuel battery generates electricity, and the motor is driven by the force of the generated electricity. The MCU controls the inverter with a pulse width modulation (PWM). The DC/DC converter converts the power generated in the fuel battery to supply the converted power as power of various types of electric field loads. The inverter switches DC voltage output from the fuel battery according to control of the MCU to convert the DC voltage to three-phase alternative current (AC) and supply the same as drive power of the motor.
A DC link capacitor is applied to the inverter that supplies the drive power to the motor. A MLCC (multi layer ceramic capacitor) module may be applied as the conventional DC link capacitor. The conventional MLCC module uses a plurality of aluminum electrolytic capacitors.
The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.
When a plurality of aluminum electrolytic capacitors is used as a conventional MLCC module, electrolyte is used and thus unique resistance is high, decreasing equivalent series resistance (ESR) characteristic and insulation resistance (IR) characteristic. Since the IR characteristic is decreased, impedance characteristic is also deteriorated.
The present invention is conceived to solve the above-described problems and thus an aspect of the present invention provides a MLCC module that can use, as a dielectric substance, ceramic with a high dielectric constant and thereby can enhance the high capacity regardless of a small size and also can obtain low ESR characteristic and low IR characteristic and also can improve heat-dissipation characteristic.
Another aspect of the present invention also provides a MLCC module that can extend the horizontal length of a MLCC module with respect to the vertical length thereof and thereby can improve ESL characteristic.
According to an aspect of the present invention, there is provided a MLCC module including: a plurality of first ceramic sheets, each including a plurality of first internal electrode portions; a plurality of second ceramic sheets, each being disposed between the plurality of first ceramic sheets respectively to include a plurality of second internal electrode portions; a plurality of external electrode portions being connected to the plurality of first internal electrode portions, respectively; a plurality of clamp lead electrode portions being connected to the plurality of external electrode portions to input and output electrical signals, respectively; and an epoxy molding compound (EMC) molding member sealing the plurality of first ceramic sheets, the plurality of second ceramic sheets, and the plurality of external electrode portions to expose one ends of the plurality of clamp lead electrode portions, respectively.